Steps to reproduce the error:
Login to Citrix cloud portal and launch the Studio.
Select the Policies Tab in the cloud hosted Studio.
Navigate to Session printers and add new printer.
Browse the Print server using the UNC path and click browse.
It times out
If the server and the printers are added manually using the UNC path the OK button to finish the wizard is grayed out.
To resolve this issue:
Download the Citrix Group policy management template - CTX220345 - Managing Group Policies for Citrix Cloud From Local Group Policy Management Console .
Follow the instructions mentioned in the article and configure the "Session printer" policy here.
Cloud connector does not have SMB access to the print server.